1. Field of the Invention
The present invention relates to a microphone circuit, and particularly to a multifunctional microphone circuit.
2. Description of Related Art
Generally, microphone circuits can be classified into differential microphone circuits and single-ended microphone circuits. A differential microphone circuit outputs both a forward signal and a reverse signal to transmit information together resulting in a relatively higher acoustic quality. A signal-ended microphone circuit outputs only a forward signal to transmit information resulting in using relatively less electric power than the differential microphone circuit.
A portable electronic device, such as a mobile phone or a personal digital assistant (PDA), often employs both a differential microphone circuit and a single-ended microphone circuit. In manufacture, the two microphone circuits are usually fabricated as chips and installed in the portable electronic device. In use, the two microphone circuits can be selected. However, the process of respectively fabricating the two microphone circuits as chips and installing them in the portable electronic device may be expensive and time-consuming. Furthermore, a volume and weight of the portable electronic device may be increased.
Therefore, there is room for improvement within the art.